Color motion-picture photography



F. T. OGRADY COLOR MOTION PICTURE PHOTOGRAPHY Filed NOV. 26. 1919 ug. )14, i923.

Parenteel aeg, ie', raza.

narran stares intatta rentrant orticao FREDRICK THOMAS OGIADY, OF FLUSHING, NEW' YORK. i

COLOR MOTKON-PICTURE PHOTOGRAPHY- `Apploationr led November 26, 1919. Serial No. 340,924.

To all whom t may concern Beit knovvn that l, FREDERICK THOMAS OGRADY, a citizen of the United States,\and

tures innatural colors by the use of single the pictures.

emulsion coated motion picture films.

c The methods of' color motion picture photography heretofore used, involved, or required the use of, complicated and extensive devices and apparatus in the prepara tion of the lm and in the projection of rThe cameras and projection apparatus used in connection with these old methods are provided with `special attachments for color-lilters.

double the number of exposures shall be made as in the ordinary monochrome pic/- ture production methods, and obviously this requires double the length of hlm. This f method also requires that the tilm shall have,

during the operation of both taking and projecting the pictures, twice the speedas the ordinary monochrome motion picture lm. Such increase in speed involves prohibitive expense and complicated -and expensive cameras and projectors for the manipulation of the tilms; also this rapid changing trom one 'color to the other causes color pulsation and fringingjof color, which' in turn Whenviewed on the screen, cause considerable optical discomfort to the observer. Other methods involve the use or double emulsion coated llms, which have to undergo the `double operation or printing,

Asuperimposing of the two images, immersion in numerous color tinting and toning solutions, Water-proong etc., the results oiv which are not onlyunsatisfactory, but en tirely uncommercial.

lin carrying out this invention a standard single emulsion coated photographic negative lm which has been rendered sensitive to all the colors or the spectrum, isv

used. Such films are known as panchromatic emulsion ilms.` To this negative hlm, on the emulsion side are applied color-lters. The film is then exposed in theusual Way in a standard motion picture camera and a @ne of the best known of these old methods requires that multiplicity of exposures are made in sequence, the exposed areas being close to-v ether and side by side throughout the engthf of the iilm. The color-filters are then Washed `from the iilm and the negative then developed. From the negative thus produced a positive print is made on a .standard positive tilm in the ordinary Way on any standard motion pictureprinting machine. After this positive print has been developed and dried the color-lters are applied thereto in positions corresponding identically to the positions Which said coiorhlters occupiedjon the original negative hlm. After the color-filters have been applied to the standard positive film, the film may be used inthe ordinary standard projecting apparatus Without the use of any additional attachment for color-filters or screens, andy the film may be moved through the projecting' machine at the usual or standardv l speed.

@ne of the main objects of this invention is to provide a method of makingv motion pictures in natural colors whereiny a standard panchromatic. negative, and 'a` single emulsion coated positive film may be used, whereby vthe actual photographing and Vprojection may be done on any standard motion picture camera and projector, at the standard speed of sixteen pictures per second.

There are other important objects and adyvantages or the invention which will appear' hereinafter, Y i f ln the drawings:

Fig. l is a detailview ot a portion of a negative hlm ruled with the color-lter lines, said lines being greatly exaggerated in width;

Fig. 2 adeta-il vienl of three plates to be photographed, said plates being colored blue, red and green;

Fig. 3 a detail viewer apart of a negative hlm as it appears after photographing the colored plates Villustrated in Fig. 2;

Fig. d a detail view of a part of a positive hlm printed from the negative film shown in Fig. 3; and

Fig. 5 is a similarvievv of lthe positive hlm shown in Fig, l ater the color-lter lines have been marked thereon to correspond with the original color-lter markings or the negative hlm. o 7

carrying this invention into effect aetandard single emulsion coated negativ@ rra lil@

film is marked longitudinally with a lmultiplicity of fine color-:lter lines. As indi? cated in Fig. l these color-filter lines run side by side close together and cover the en\` tire emulsionv coated portion of the iilm.

Preferably these color-lters are red, green "and blue or blue-violet, as indicated by the letters R, G5, B rkin Fig. 1. These color-filters are repeated in the stated sequence throughout the width of the film. :Preferably these color-filters are very fine, approximately one thousandth of an inchwide so that, there willj` be approximately! one thousand, of these color-filters to each inch of film measured transversely. These colorfilter lines are ruled ormarked directly onV the emulsion side of the film; and ashereinbefore set forth a single emulsion coated"- panchromaticr negative film is used.

The color-ilter lines may be marked upon the lm by any suitable means, but preterably bysomefmeans having properly spaced rullng or marking devices. These devices may be mounted in any suitable manner. lit

is` thought unnecessary to illustrate and dev scribe indetail a marking machine, as any suitable machine may be used for that purpose. f f

A negative film marked with the filters may be exposed in an ordinary motion picture camera and a multiplicity of picture areas are exposed, said picture areas being arranged in sequence and close together side byside throughout the length ofthe exposed m, the rate of exposure being the same as when a plain monochromatic single emulsion coated negative hlm is used. 4llt is unnecessary to use any additional color-filtersV `or screens or other devices except that it is I camera the photographic images are affected lill)k by the color-lter lines on the lm in such a way that the colors of the object photographed are ltered, that is to say, are pervmitted to pass only through their respective color-lters, so' that the red rays will pass only through the red color-filters, green rays only through the een color-filters, while blues and blue-vio et rays will pass only through the blue or blue-violet color-lters. The result is that each particular color after exposure of the film in the camera, is represented by a series of graduated dark lines on the emulsion'of the lm, with intervening clear spaces where the lter lines complementary Lto the color photographed has pre ventedrexp'osure-.of the emulsion.` This will be readily understood by reference to Figs.n 2 and 3. Fig'. 2 illustrates a blue background 1, a red plate 2 and a green plate 3, p these two plates being placed against vthe* blue background. Fig. 3 represents a photo graphic color record of the blue background and the red and green plates illustrated in Fig. 2. The dark lines 2a in F ig. 3 repre-v tol which have passed. through the green filter'v lines on the negative hlm; and the dark lines 12l represent the ed'ect of the blue rays that haveA passed through the blue or blue-violet Y lter lines on the negative lm from the blue background l. The clear spaces intervening between the dark lines la represent the spaces on the film that were covered by `the red and green lil-ter lines.l The clear spaces between 'the dark lines 2avv represent the spaces on the lm that were covered by the blue and green color-filter lines onthe negative tilm while the clear spaces between the vdark lines 3a represent the spaces that were" covered by the blue and red filter lines.

After the negative lm is exposed it is Washed in runnin water or other suitable liquid to complete y remove the color-filters. This must be done before ythe negative is developed. This is most important for the reason that positive films are made from the negative by printing in the ordinary way as in makingimonochro-me prints. lf the lilters were not 'washed from the negative they would interfere with the action of the'light used in printing, and prevent it passingv through the'color-filter lines. After the development a photograph of the plates asy shown in Fig. 2 will appear as shown in Fig. 3. lit will, ot course, vbe understood that in the drawings the width of the color- `tlter lines is greatly exaggerated and that its llll

on a negative ilm of normal size these lines will be very ne. After it is developed the negative film has the appearance of a black and white-negative but is lined to correspond to the lines of the color-filters through which the exposure was made. lit also possesses latent color values ot the object photo,-

raphed, in monochrome form. These lines, owever, are so ne as to be hardly perceivable with the naked eye. @i course, it is manifest that these lines run longitudin vnally through the length ot the Elm and 'occur in each exposure or picture on the film.

litter .the negative tlm is developed al positivel print is made from` it in theL ordinary way on any standard motion picture machine, using standard positive lms, a

multiplicity of picture areas being thus printed, said pictur e areas being arranged 1n sequence close together and extending throughout the length of the exposed film. A positive lm print made from the negative shown in F ig. 3 will appear as. shown in Figli. fThe emulsion? will be affected by vthe light passing through the clear spaces jchine in precisely the same Way that the negative -film was passed and the colorilters are placed on the positive film.V .Tn

the development of the negative film there will be a certain minute-transverse shrink-` age. InV the development of the positive film -there, also will be a minute transverse I vices areso adjusted that their particular` shrinkage. The devices for applying the color-filter lines to the positive film must compensate for the minute transverse shrinkage of the films during development and drying.v -lfn applying the color-filter lines te the positive print, the ruling decolor lines correspond and apply themselves to their particular color representations in the positive printf as follows: The blue lter` lines will cover the clearvspaces la in the blue background; the red filter lines will covertyhe clear spaces formed bythe dark lines Y2 and the,r green lter lines Will cover the clear spaces formed by the vdark lines -3, When thepositive film has been lined or'marked with the color-filters it` has the appearance illustrated in Fig. 5. The positive film thus produced can be projected on .a `suitable screen by means` of any standard motion picture machine Without additional filters' or screens or other attachments and may be run a-t the same rate of speed as Y standard monochrome motion picture records, and the pictures on the viewing screen will be in substantially the natural colors `of the object Aphotographed and with a marked stereoscopic effect. This stereoscopic e'ect results from the opaque lines in the positivefilniand gives tothe photographed object an appearance of relief and solidity.' This is a marked improvement over the ordinary monochrome moving picture, and.. is in addition to the color e'ect secured.

The color lter lines are straight and parallel .and extendlongitudinally yof the lm in' the direction of its movement through the camera, printer or ,projecting machine, and the" said lines extend continuously overl a series of pictures-upon the fihn. There is a distinct advantage in such I an arrangement of the color filter lines inasmuch as it avoids an annoying and injurious effect upon the eyes of ,anobserver such as would be caused by any other arrangement of the lines. In the longitudinal travel of motion picture films through `the camera or the printer the said films are carefully guided against lateral displacement and as a consequence, most of the successive picture areas are properly placed in alinement upon the films. lt is impossible on the other hand to evenly space the picture areas along the filnLoWing to several` causes such as the stretching of the A-:film and wear in the connections between the film and the feeding mechanism: The film may also be subjected to stretching and inaccurate feeding as it is passed through the projecting machine and these defects ,l

will increase with repeated use of the film. The picturel when projected is therefore, constantly chan ing its vertical position slightly, 'or vibratlng up and down upon the screen.VV Assuming that the v color filter lines were arranged upon the lm in other ways than the one shown, as for instance, transversely or obliquely of the film, it is obvi ous that the color lines which are projected upon the screen will yconstantly vibrate up and down as the picture vibrates and subject, the observers eyes to an annoying andf poss1bly lnjurlous strain, the colors render-` 1040 ing the vibration particularly trying to the eyes. My arrangement of the color filter` lines so as to extend vertically andcontinously through a series of picture areas in the direction of their movement overcomes jthis diculty owing to the fact thatl the color lines projected upon the screen from one picture area will occupy the same lateral positions upon the screen that they oc" cupiedI when projected from a preceding ill@ picture area and the said lines Will vibrate A only in the dir'ection of their length, Which vibration will impose no strain upon the eyes. i v i "While it is preferredv to use the three color-filters namelyred, green and blueor blue-violet, it is manifest that good results can be' obtained by the use of other color( combinations. lit is obvious that the colorrulingmachine may be readily changed to color-filter on films.

ieu

adapt it for placing the `desired number of--,

Whati claim is:-

1. The method of making positive lms for the projection of motion pictures yin colors consisting in first marking on the emulsion side of a negative -film a multij plicity of fine longitudinallyI extending straight, parallel colorfllter lines, said colorfiltcr lines extending over a multiplicity of 15 veloping said positive film to fix the images picture 'areas in the direction of their movement and being arranged side by side and covering the entire emulsion coat, exposing the filter area of the said marked 'negative lmin a camera to obtain a series of images thereon in sequence on a multiplicity of picvture areas, Washing the color filter lines from the exposed negative film and then de'- veloping said lm to fix the images there- I onymaking a print from said negative iilm' on a positive film to ,produce the sequence of pictures arranged close ltogether and covering a multiplicity of' picture areas aml rangedlongitudinally of theAfilm, anddethereonand then marking on the positive film longitudinally extending color filter lines, said lines being continuous over a multiplicity of picture areas arranged close together and in sequence longitudinally of the lm and corresponding exactly 'in number and position and character With the color filter lines marked oi'iginally on the negative film.

2. The method of making positive films for the projection of motion pictures in colors consisting in first providing a negative lture areas arrange recente exposed negative lm and then developing said film to fix the images-"thereon, making la print from said negative film on a positiver film' to produce the sequence of pictures arranged close together and covering a multiplicity of picture areas arranged close together and coverin a multiplicity of piclongitudinally of the film, andV developing said positive film to fix the images thereon and then marking' on the positive film longitudinally extending color filter lines, said lines being continuous over a multiplicity of picture .areas arranged close together and Vin sequence longitudinally of the 'lm and corresponding exactly in number and position and character With the color filter lines provided originally'for the negative lm.

3. A positive lm for motion picture projection having straight, parallel color` value lines yformed in the emulsion coating during the process of printing, said lines running longitudinally of the'film side by side and being continuous'over a multiplicity of picture areas arranged close together .andjin 'sequence longitudinally ofthe. hn and eX- tending inv the .direction of its movement,.

and color filter lines marked on the said emulsion coating ofthe film directly over and superimposed upon the color value lines formed in the emulsion, each of said color filter lines being continuous and extending over a multiplicity of picture areas and corresponding in color to the color value lines i covered by it. v

This` specifi/cation signed this twentyfourth day of November, A. D. 1919.

' FREDERlCK THOMAS, GRADY. 

